Step 7: Eat and drink Don’t forget to eat and drink. Your body needs fuel to produce heat, so stay well fed, and don’t skimp on the fats. Also, drink water, which will help your body process those calories.

TIP: Stay away from alcoholic and caffeinated beverages. Both will dehydrate you, making it harder for your body to generate heat.

Step 8: Stick together If you’re in this with other people, stay in the same room, or huddle together, so that you can benefit from each other’s body heat.

FACT: Though igloos are made of snow, parts of the interior can reach 61° Fahrenheit, just from body heat.